Career
Türn played in numerous Estonian championships. In 1923, he took 2nd, behind Paul Rinne, in Tallinn (1st EST-ch). In August/September 1936, he played on fourth board in the unofficial Chess Olympiad in Munich (+8 –4 =7).
In July/August 1937, he played on fourth board at the 7th Chess Olympiad in Stockholm (+1 –6 =4).
During World World War II, Türn played in the Estonian championships, although the country was occupied by either the Soviet Union or Germany. In 1941, he tied for 1st with Feliks Kibbermann in Tallinn (11th EST-ch), but took the title after a play-off match (+3 –0 =1).
In 1942, he took 2nd, behind Paul Keres, in Tallinn (12th EST-ch). In 1944, he tied for 1st-2nd with August Eller in Viljandi (14th EST-ch).
He also played draughts.
He was also co-author of the first Estonian book of draughts (Kabemängu õpik, 1951). Johannes Türn vs Kazimierz Makarczyk, Munich 1936 (ol), Semi-Slav Defense, Marshall Gambit, D31, 1-0
Johannes Türn vs Teodor Regedziński, Buenos Aires 1939, 8th Olympiad, Queen's Gambit Declined, Semi-Tarrasch, D41, 1-0.